Highly Reliable Diode-Clamped Resonant DC/DC Converter for Overloaded Automotive Applications

This article proposes a diode-clamped resonant dc/dc converter having overload capability. The electric motor is able to demand short-time peak torque during sudden acceleration phase or long-time excessive torque when the automobiles are overloaded; it can also suffer from a short circuit fault of winding. Then, conventional full-bridge resonant dc/dc converters employing the secondary-side switching undergo very high current spike at the semiconductor devices on the secondary side when the load exceeds its threshold. By incorporating resonant diode-clamped cell, we have removed the high current spike occurred at the secondary-side power devices. In addition, its secondary-side switches can be completely turned off with zero-voltage-switching so that all of the active devices can be softly switched. Furthermore, the proposed converter can survive when its output nodes are short-circuited. Comparisons present the benefit of the proposed converter over conventional converters that use the secondary-side switching.